Initiators are generally compounds with weak bonds that are easily decomposed into active species, in which covalent bonds have two forms of homolysis and heterolysis. Also called starter. A chemical carcinogen that can transform normal cells into dominant tumor cells. The initiator has the following characteristics: it is carcinogenic and must be given before the growth-promoting agent. A single exposure or exposure can produce an effect, and its effect can be cumulative and irreversible, and there is no threshold; it can produce electrophilic substances and Cell macromolecules (DNA) are covalently bound, and the vast majority are mutagenic. For example, trans-4-acetamidostilbene is an initiator.

Initiators are substances that initiate the polymerization of monomers. The active centers of unsaturated monomer polymerization include free radical type, anion type, cation type and coordination compound, etc. At present, the most widely used in the adhesive industry is the free radical type, which exhibits unique chemical activity, and can be used under heat or light. Under the action of the covalent bond, two free radicals are generated, which can initiate the polymerization reaction.

Initiators play a great role in the research and production of adhesives and sealants. Acrylates are solvent-polymerized to prepare pressure-sensitive adhesives, and vinyl acetate is solvent-polymerized to manufacture construction adhesives and building sealants. Synthesis of styrene-acrylic emulsions, ethylene-propylene emulsions, and VAE emulsions , styrene-butadiene latex, neoprene latex, white latex, etc., grafted neoprene adhesive, sBs grafted adhesive, unsaturated polyester resin cross-linking curing, anaerobic adhesive curing, fast-setting acrylate structural adhesive Curing, etc., must use an initiator. The initiator can directly affect the smooth progress of the polymerization process, the rate of the polymerization reaction, and the shelf life of the product.